Expanding arbor

ABSTRACT

An expanding arbor having a pin with cam slots receiving expanding wedges and an adapter for effecting expanding movement of the pin relative to the arbor.

United States Patent Anthony [451 Oct. 10, 1972 [54] EXPANDING ARBOR 3,462,l62 8/1969 Stoefler.....- .279/2 [72] Inventor: Russell W. Anthony, Harper Woods,

Mich. Primary ExaminerGil Weidenfeld [73] Assignee: Lear Siegler, Inc., Santa Monica, Atmmey whittemre Hulben Belknap Calif. 221 Filed: March 23, 1971 [57] ABSTRACT [21] APP] No: 127,147 An expanding arbor having a pin with cam slots receiving expanding wedges and an adapter for effecting expanding movement of the pin relative to the ar- [52] US. Cl ..279/4, 82/44 ban [51] Int. Cl. ..B23b 31/40 [58] Field of Search ..279/2, 4, 50, 43, 57; 82/44; 408/155; 51/338; 242/721 [56] References Cited 5 Claims, 1 Drawing Figure UNITED STATES PATENTS 3,492,914 2/1970 Anthony...., ..279/2 X 1 I i E 07 id id M l 17 p I. j I,

/d r hll 5 rl'l 1/ 44 PKTENTEUDBT 10 I972 INVENTOR.

F TUFNL' EXPANDING ARBOR BRIEF SUMMARY OF THE INVENTION limited axial movement thereof to move the wedges radially outwardly.

BRIEF DESCRIPTION OF THE DRAWING The FIGURE is a longitudinal section through the expanding arbor.

DETAILED DESCRIPTION The expanding arbor assembly is intended for use with work rotating means such as a headstock and for this purpose the arbor is provided with a flange l2 apertured as indicated at 14 for attachment to the headstock. A cylindrical locator disc 16 is applied to the inner face of the flange l2 and is received in a shallow cylindrical recess 18 and attached to the arbor by the screws 20.

The forward end of the arbor is reduced as indicated at 22 to form the work supporting portion, and a cylindrical opening 24 extends through the forward end of the arbor. Adjacent the forward end of the arbor there are provided a multiplicity, usually four, wedge receiving slots 26. Each of these slots receives a wedge 28 the inner surface of which is inclined as indicated at 30.

An elongated cylindrical expander 32 is mounted for longitudinal movement in the cylindrical opening 24, the forward end of the expander being provided with slots having inclined bottom surfaces 34 engageable with the inclined inner edges of the wedges 28.

Each of the wedges is provided with an outer recess 36 and spring means 38 are provided in the recesses urging the wedges 28 inwardly to seat the inclined inner edges thereof against the bottom surfaces of the slots at the forward end of the expander. The outer end of the elongated cylindrical opening 24 is closed by a plug 40 which may be formed of a synthetic rubber. In order to effect outward cammed movement of the wedges 28 in order to expand them into firm gripping relation with a cylindrical surface on a work piece, the inner end of the expander 32 is connected to an adapter 42 which at its inner end has a threaded opening 44 for receiving the forward end of an actuating rod 46 adapted to connect the adapter to a piston and cylinder device. The forward end of the adapter 42 is provided with a cylindrical recess 48 which receives the inner end of the expander.

. The arbor is provided with an enlarged recess or chamber 50 in which the forward end of the adapter is longitudinally movable. Since the expanding arbor is intended to drive the workpiece supported thereby, it is essential that the entire assembly rotate as a unit. The keys or wedges 28, which are received in the slots 26 formed in the arbor, of course are required to rotate therewith. In addition, the inner edge portions of the wedges 28 are received in the inclined slots having the bottom walls 34 and accordingly, the expander 32 is required to rotate with the keys. It is desirable however, to provide driving means which prevents binding of the wedges 28 and this means takes the form of a pin 52 which extends through cylindrical openings 54 and 56 formed respectively in the inner end of the expander 32 and the outer end of the adapter 42. The ends of the pins extend into longitudinally elongated slots 58 formed in the arbor l0 and which communicate with enlarged cylindrical threaded openings 60 which receive threaded plugs 62. The dimensions of the slot 58 are such as to permit free longitudinal sliding movement of the assembly comprising the adapter, expander and pin, while preventing rotation between these parts and the arbor 10.

Adapter 42 has a shoulder 66 so that its longitudinal movement is limited between a first position when this shoulder engages disc or plate 16 and a second position when the adapter bottoms in the chamber 50. This prevents damage to pin 52, or to spring 38 if the machine is cycled empty.

In use, the expander 32 is retracted downwardly as viewed in the FIGURE, which permits the spring means 38 to contract the wedges 28. At this time a work piece is applied over the reduced outer end of the arbor and pressure is applied to move the expander 32 forwardly (upwardly in the FIGURE) in order to cam the wedges 28 outwardly into firm engagement with the opening in the work piece. Proper registration between the camming slots at the outer end of the expander and the slots 26 formed in the reduced outer end of the arbor is maintained by the pin 52, the outer ends of which are closely engaged by the sides of the elongated slots 58.

What I claim as my invention is:

1. An expanding arbor assembly for attachment to a rotatable headstock comprising an arbor having an elongated cylindrical opening therethrough, a plurality of slots adjacent the forward end of the arbor communicating with the cylindrical opening, elongated wedges slidable radially in the slots, spring means urging said wedges radially inwardly, the wedges having inclined inner edges, an elongated expander movable longitudinally in said cylindrical opening, the forward end of said expander having a plurality of slots in registration with the slots in the arbor, the slots in said expander having inclined bottom camming surfaces engaged with the inclined inner edges of said wedges, said arbor having an enlarged cylindrical chamber at its inner end concentric with the cylindrical opening therethrough, an adapter having a cylindrical portion slidable longitudinally in said chamber and having a cylindrical recess which receives the inner end of said expander, said adapter and expander having aligned cylindrical openings, a pin received in said last named openings coupling said pin and adapter, the ends of said pin extending laterally beyond the sides of said adapter, said chamber having elongated longitudinally extending guide slots in which the ends of said pin are received to provide for longitudinal movement of said adapter and expander while preventing rotation between the expander and arbor and retaining the slots at the forward end of said expander in exact registration with the wedge-receiving slots in said arbor.

2. An assembly as defined in claim 1 in which threaded openings are provided in said arbor in comapertured plate at the outer end of said chamber, said adapter having a shoulder engageable with said plate to limit movement of said adapter relative to said arbor in one direction and having an end surface engageable with the bottom of said chamber to limit movement of said adapter in the opposite direction to prevent damage to said pin by engagement with the ends of said guide slots and damage to said spring means.

a: a: a: a: 

1. An expanding arbor assembly for attachment to a rotatable headstock comprising an arbor having an elongated cylindrical opening therethrough, a plurality of slots adjacent the forward end of the arbor communicating with the cylindrical opening, elongated wedges slidable radially in the slots, spring means urging said wedges radially inwardly, the wedges having inclined inner edges, an elongated expander movable longitudinally in said cylindrical opening, the forward end of said expander having a plurality of slots in registration with the slots in the arbor, the slots in said expander having inclined bottom camming surfaces engaged with the inclined inner edges of said wedges, said arbor having an enlarged cylindrical chamber at its inner end concentric with the cylindrical opening therethrough, an adapter having a cylindrical portion slidable longitudinally in said chamber and having a cylindrical recess which receives the inner end of said expander, said adapter and expander having aligned cylindrical openings, a pin received in said last named openings coupling said pin and adapter, the ends of said pin extending laterally beyond the sides of said adapter, said chamber having elongated longitudinally extending guide slots in which the ends of said pin are received to provide for longitudinal movement of said adapter and expander while preventing rotation between the expander and arbor and retaining the slots at the forward end of said expander in exact registration with the wedge-receiving slots in said arbor.
 2. An assembly as defined in claim 1 in which threaded openings are provided in said arbor in communication with the slots which receive the ends of said pin, and plugs in said threaded openings.
 3. An assembly as defined in claim 1 in which the open end of the elongated cylindrical arbor receives a sealing plug.
 4. An assembly as defined in claim 1, and actuating means connected to said adapter operable to effect longitudinal movement of said adapter and expander relative to said arbor.
 5. An assembly as defined in claim 1 comprising an apertured plate at the outer end of said chamber, said adapter having a shoulder engageable with said plate to limit movement of said adapter relative to said arbor in one direction and having an end surface engageable with the bottom of said chamber to limit movement of said adapter in the opposite direction to prevent damage to said pin by engagement with the ends of said guide slots and damage to said spring means. 